WordNet
n. riding along a roughly blazed path
Wikipedia
Trail riding is riding outdoors on trails, bridle paths, and forest roads, but not on roads regularly used by motorised traffic. A trail ride can be of any length, including a long distance, multi-day trip. It originated with horse riding, and in North America, the equestrian form is usually called "trail riding," or, less often "hacking." In the UK and Europe, the practice is usually called horse or pony trekking.
The modern term also encompasses mountain biking, mixed terrain cycle-touring, and the use of motorcycles and other motorized all-terrain vehicles. It may be informal activities of an individual or small group, or larger events organized by a club. Some equestrian trail rides in the USA are directed by professional guides or outfitters, particularly at guest ranches. In some parts of the world, trail riding (of whatever kind) is limited by law to recognized, and sometimes function-specific, trails that are waymarked. In other places, trails may be less maintained and more natural. Trail riding can include other activities, such as camping, hunting, fishing, orienteering and backpacking.